Welcome to Apnea Board ! As a guest, you are limited to certain areas of the board and there are some features you can't use. To post a message, you must create a free account using a valid email address.
Login or Create an Account

The reason I suggested the 10 amp fuse was because the ResMed converter pdf says it uses a 20 amp fast-blow fuse. In our case, operating at 24 volts requires half the current (10 amps).

Well, for some reason I decided to look at the pdf again and I noticed that the converter will run on 24 volts too. That certainly adds some versatility.

Just something to keep in mind.

Just my personal opinion. My posts are not medical advice or a statement of fact. Please consult a qualified physician or other qualified medical personnel. Please comply with all applicable laws, codes, regulations, and protocols.

(06-12-2016, 11:27 PM)verbatim1 Wrote: I will google for a freeware schematic program (if they exist), which would make things far simpler to draw (and better looking).

Check out DipTrace. It's what I use and there's a freeware version.

Just my personal opinion. My posts are not medical advice or a statement of fact. Please consult a qualified physician or other qualified medical personnel. Please comply with all applicable laws, codes, regulations, and protocols.

(06-12-2016, 11:59 PM)sdb7802 Wrote: The reason I suggested the 10 amp fuse was because the ResMed converter pdf says it uses a 20 amp fast-blow fuse. In our case, operating at 24 volts requires half the current (10 amps).

Thanks for explaining that we only need to worry about half the current, so, we'll stick with a 10A fuse.

In addition, it would be nice to see if ResMed offers a BATTERY 24V supply, because they'll specify the voltage range.

For example, in this "ResMed Power Station (RPS) II" factsheet PDF, they say their Lithium Ion battery (which has a different range than SLA batteries), is 24 to 26VDC plus or minus 1/2 volt so that's 23.5 to 26.5 volts for that one supply.

(06-12-2016, 11:59 PM)sdb7802 Wrote: Well, for some reason I decided to look at the pdf again and I noticed that the converter will run on 24 volts too. That certainly adds some versatility.

I searched for that PDF and I think I found a 16-page user guide for the 12/24VDC DC-to-DC converter for the S9 here:[link to commercial DME website removed per rules]
(I presume the A10 is the same as the S9?)

-----Moderator Action: Link Removed

To maintain our status as an educational organization, the only commercial links allowed in this forum are to CPAP-related manufacturer websites. This is stated in the Apnea Board Rules with details given in the Commercial Links Policy section.

Just my personal opinion. My posts are not medical advice or a statement of fact. Please consult a qualified physician or other qualified medical personnel. Please comply with all applicable laws, codes, regulations, and protocols.

The LT1038/LM338 are linear series pass regulators which means the output voltage is always lower than the input voltage. The L4970A is switching buck (step-down) regulator which has the same limitation.

A buck-boost regulator will output the correct voltage whether the input voltage is lower or higher than the input voltage (within limits). The ResMed converter will do this for either a 12V or 24V battery input.

Just my personal opinion. My posts are not medical advice or a statement of fact. Please consult a qualified physician or other qualified medical personnel. Please comply with all applicable laws, codes, regulations, and protocols.

(06-13-2016, 08:16 PM)OMyMyOHellYes Wrote: Is the discussion past the point, in terms of required effort, of making the expensive resmed power box look attractive?

As a dedicated tinkerer, I can't believe I just said that.

OMMOHY

Really attractive. I'll run my battery test and if it works; I recommend we post the simple circuit for those who want to tinker.

Just my personal opinion. My posts are not medical advice or a statement of fact. Please consult a qualified physician or other qualified medical personnel. Please comply with all applicable laws, codes, regulations, and protocols.

Useful Links

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.